Several Ways to Save a Diode

[Isoleucine]

Since this is my 1, 2, 3, 4, FIFTH diode that i broke... 3 of which were PHR's and two of them were 445s :undecided:

I decided once again to share not only the experiences, but my knowledge as well. Here are the things I learned after breaking FIVE diodes, in the order I learned them in.

Now, I must once again save up my spare dollars for another 445 diode... :gun:

1. Always solder quickly.

WHY? You do NOT want to overheat that diode. The diode typically breaks within 10 seconds of heating. You want to solder the wires and/or leads to the diodes within THREE SECONDS. If this proves to be difficult, flux up the wire and the pin of the diode real well, and then touch the joint with a solder-blobbed iron to finish off the joint. Make sure your iron tip is clean and residue free before you start.

2. Build a TEST LOAD.

WHY? You should probably want to adjust your power before you hook up a diode. To build one, you will need 3-6 1N400x rectifier diodes and a 1 ohm resistor. Connect each rectifier in series and the one ohm resistor last. To begin testing, you always want to start out with a lower current, so that you can diagnose problems that may be affecting the output of your diode. Then, hook up the entire setup to the output of your driver. Your built circuit will heat up, so make sure you remove the power supply before you solder the on the circuit leads to the output. Then, hook up your power, and measure millivoltage across the one ohm resistor. This will be your mA, milliamperes. This works because of OHMS law. More on that later, and you can find info about it on several threads here.

3. Connect the power supply LAST.

WHY? Well, this is important. I one connected the power supply and then soldered on my diode without a switch. Because the diode would switch on, and then off when the diode/driver leads would touch intermittently, the diode was shorted. Always do this last, as it will, undoubtedly kill your diode if you connect and disconnect the diode from the driver. And you should always place the switch between the power supply and the driver. Drivers that do this are called current-source mode drivers. Look this information up on your driver's manual.

4. USE the HEATSHRINK.

WHY? Well the heatstrink is important for several reasons. One, it protects your joints from breaking or cracking, and it also (big bonus) isolates the joint electrically. This is HIGHLY important because it will prevent shorts in your wires. I once connected my 445 diode all nicely and tidy with the wires naked. Then, without thinking, I twisted the wires when I was screwing on the last component (literally the retainer ring of the C6), and the wires shorted. And it helps to aesthetically improve the looks of your wires.

5. And lastly, RESEARCH!

If you haven't already, you should always be knowledgeable of your project. Know the components of your laser, safety apparatus, and other miscellaneous parts. I once broke a PHR without knowing why... took about 15mins and found out that I shorted it during my preassembly stages. Use a steady hand and work slowly. Typically for me, assembling a laser from zero to hero takes about 2 hours, excluding glue drying time.

Hope this helps, Iso.

 

[offroadfreak8582]

Nice one

But there is always a change your diode is DOA or it just does not can take high currents like mine

But nice thread should be stickied!

Greetings,,

 

[Benm]

Starting out with a low, safe, current is always a good idea: you can see if your diode is actually working, and you will also be able to notice some problems like poor thermal coupling with the module before actually damaging the diode.

As for the speed at which you need to solder:

Insert the diode into a module -before- soldering at all times. The module will heatsink your diode even when you heat up the pins with the soldering iron. The construction of laser diodes is such that heat conduction from the pins is easily offset by the heatsinking of the module, and you can take much longer than a few seconds if you need to (using an iron at proper temperature, ofcourse).

The risk of damaging a laser diode by soldering heat is often overestimated - heat isn't that dangerous to a laser diode as long as its not operating. Obviously you should allow ample time to let it cool down before powering up!

 

[Isoleucine]

I always knew about that... thinking about thermal capacities... but yeah. I understand.

Do you want me to include that in the OP?

 

[Benm]

Perhaps the part about inserting the diode into the module before doing any soldering work... as doing it in the wrong order often also complicates getting the diode into the module later on